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The hydrolysis of hydroxamic acid complexants in the presence of non-oxidizing metal ions 1: Ferric ions.

Andrieux, Fabrice Pierre Louis and Boxall, C. and Taylor, R. J. (2007) The hydrolysis of hydroxamic acid complexants in the presence of non-oxidizing metal ions 1: Ferric ions. Journal of Solution Chemistry, 36 (10). pp. 1201-1217. ISSN 0095-9782

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    Abstract

    Hydroxamic acids (XHAs) are organic compounds with affinities for cations such as Fe3+, Np4+ and Pu4+ and have been identified as useful reagents in nuclear fuel reprocessing. Acid catalyzed hydrolysis of free XHAs is well known and may impact negatively on reprocessing applications. The hydrolysis of metal-bound XHAs within metal ion-XHA complexes is less understood. With the aid of speciation diagrams, we have modelled UV-visible spectrophotometric kinetic studies of the acid-catalyzed hydrolysis of acetohydroxamic acid (AHA) bound to the model ion Fe(III). These studies have yielded the following information for the hydrolysis of AHA in the Fe(AHA)2+ complex at 293 K: (i) the order with respect to [H+] during the rate determining step, m=0.97, is the same as for the free ligand, indicating a similarity of mechanisms; and (ii) the kinetic rate parameter, k 1=1.02×10−4 dm3⋅mol−1⋅s−1, is greater than that for the free ligand, k 0=1.84×10−5 dm3⋅mol−1⋅s−1 for pH>−0.5, a result that is consistent with a Hammett analysis of the system.

    Item Type: Article
    Journal or Publication Title: Journal of Solution Chemistry
    Additional Information: The original publication is available at www.springerlink.com
    Uncontrolled Keywords: acetohydroxamic acid ; ferric ions ; complexation ; speciation ; hydrolysis ; kinetics ; NUCLEAR-FUEL ; BENZOHYDROXAMIC ACID ; ORGANIC EXTRACTANTS ; IRRADIATED FUELS ; HYDROXYLAMINE ; SEPARATION ; REDUCTION ; BEHAVIOUR ; KINETICS ; POWER
    Subjects: T Technology > TA Engineering (General). Civil engineering (General)
    Departments: Faculty of Science and Technology > Engineering
    ID Code: 26511
    Deposited By: Dr Fabrice PL Andrieux
    Deposited On: 27 May 2009 10:23
    Refereed?: Yes
    Published?: Published
    Last Modified: 24 Jan 2014 05:16
    Identification Number:
    URI: http://eprints.lancs.ac.uk/id/eprint/26511

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